Antioxidant Therapy in Inflammatory Bowel Diseases

Potential of nutraceuticals in celiac disease

Celiac Disease (CD) is the most common hereditarily-based food intolerance worldwide and a chronic inflammatory condition. The current standard treatment for CD involves strict observance and compliance with a gluten-free diet (GFD). However, maintaining a complete GFD poses challenges, necessitating the exploration of alternative therapeutic approaches. Nutraceuticals, bioactive products bridging nutrition and pharmaceuticals, have emerged as potential candidates to regulate pathways associated with CD and offer therapeutic benefits. Despite extensive research on nutraceuticals in various diseases, their role in CD has been relatively overlooked. This review proposes comprehensively assessing the potential of different nutraceuticals, including phytochemicals, fatty acids, vitamins, minerals, plant-based enzymes, and dietary amino acids, in managing CD. Nutraceuticals exhibit the ability to modulate crucial CD pathways, such as regulating gluten fragment accessibility and digestion, intestinal barrier function, downregulation of tissue transglutaminase (TG2), intestinal epithelial morphology, regulating innate and adaptive immune responses, inflammation, oxidative stress, and gut microbiota composition. However, further investigation is necessary to fully elucidate the underlying cellular and molecular mechanisms behind the therapeutic and prophylactic effects of nutraceuticals for CD. Emphasizing such research would contribute to future developments in CD therapies and interventions.

Hydroethanolic Extract of Lepidium apetalum Willdenow Alleviates Dextran Sulfate Sodium-Induced Colitis by Enhancing Intestinal Barrier Integrity and Inhibiting Oxidative Stress and Inflammasome Activation

The prevalence of ulcerative colitis (UC) has surged in Asian nations recently. The limitations of traditional drug treatments, including biologics, have spurred interest in herbal medicines for managing UC. This study aimed to elucidate the protective mechanisms of hydroethanolic extract from Lepidium apetalum Willdenow (LWE) on intestinal integrity and inflammation in a dextran sodium sulfate (DSS)-induced colitis model of inflammatory bowel disease (IBD). Using UPLC-MS/MS analysis, eleven phytochemicals were identified in LWE, including catechin, vicenin-2, and quercetin. LWE restored transepithelial electrical resistance (TEER) and reduced paracellular permeability in IL-6-stimulated Caco-2 cells, increasing the expression of the tight junction proteins ZO-1 and occludin. LWE treatment alleviated DSS-induced colitis symptoms in mice, reducing body weight loss, disease activity index values, and spleen size, while improving colon length and reducing serum FITC-dextran levels, indicating enhanced intestinal barrier function. LWE suppressed NLRP3 inflammasome activation, reducing protein levels of pro-caspase-1, cleaved-caspase-1, ASC, and NLRP3, as well as mRNA levels of IL-1β, IL-6, and TNF-α. LWE treatment upregulated activity and mRNA levels of the antioxidant enzymes SOD1 and NQO1. Additionally, LWE modulated the Nrf2/Keap1 pathway, increasing p-Nrf2 levels and decreasing Keap1 levels. LWE also restored goblet cell numbers and reduced fibrosis in DSS-induced chronic colitis mice, increasing gene and protein expressions of ZO-1 and occludin. In summary, LWE shows promise as a therapeutic intervention for reducing tissue damage and inflammation by enhancing intestinal barrier function and inhibiting colonic oxidative stress-induced inflammasome activation.

The Role of the Gut Microbiome in Inflammatory Bowel Disease: The Middle East Perspective

The gut microbiome is of paramount importance in preserving internal balance in the gastrointestinal tract; therefore, disruptions in its regulation have been linked to the development of inflammatory bowel disease (IBD). This article explores the intricate details of the gastrointestinal microbiome as it pertains to inflammatory bowel disease (IBD), with an emphasis on the Middle East. The study reviews the typical gut microbiome, modifications in inflammatory bowel disease (IBD), determinants impacting the gut microbiome of the Middle East, and prospective therapeutic interventions.

Desloratadine via its anti-inflammatory and antioxidative properties ameliorates TNBS-induced experimental colitis in rats

BACKGROUND

Intestinal mucosal immune cells, notably mast cells, are pivotal in ulcerative colitis (UC) pathophysiology. Its activation elevates tissue concentrations of histamine. Inhibiting colonic histamine release could be an effective therapeutic strategy for treating UC. Experimental model like 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced colitis in rats mimic human IBD, aiding treatment investigations. Drug repurposing is a promising strategy to explore new indications for established drugs. Desloratadine (DES) is second-generation antihistamine utilized for managing allergies by blocking histamine action in the body. It also has reported anti-inflammatory and antioxidant actions.

OBJECTIVE

DES was investigated for its repurposing potential in UC by preclinical screening in TNBS-induced colitis in Wistar rats.

METHODS

Therapeutic efficacy of DES was evaluated both individually and in combination with standard drug 5-aminosalicylicacid (5-ASA). Rats were orally administered DES (10 mg/kg), 5-ASA (25 mg/kg), and DES + 5-ASA (5 mg + 12.15 mg) following the induction of colitis. Parameters including disease activity score rate (DASR), colon/body weight ratio (CBWR), colon length, diameter, pH, histological injury, and scoring were evaluated. Inflammatory biomarkers such as IL-1β, TNF-α, along with reduced glutathione (GSH), and malondialdehyde (MDA) were assessed.

RESULTS

Significant protective effects of DES, especially in combination with 5-ASA, against TNBS-induced inflammation were observed as evidenced by reduced DASR, CBWR, and improved colon morphology. Drugs significantly lowered plasma and colon histamine and, cytokines levels. GSH restoration, and decreased MDA content were also observed.

CONCLUSION

DES and DES + 5-ASA demonstrated potential in alleviating colonic inflammation associated with TNBS-induced colitis in rats. The effect can be attributed to its antihistamine, anticytokine, and antioxidative properties.

Cotinus coggygria Scop. Attenuates Acetic Acid-Induced Colitis in Rats by Regulation of Inflammatory Mediators

In traditional medicine, many medicinal plants are used in the treatment of various diseases caused by inflammation. The objective of the present study is to elucidate for the first time the effects of Cotinus coggygria (CC) ethanol extract (CCE) on colonic structure and inflammation of acetic acid-induced ulcerative colitis in rats. Colonic damage was assessed using disease activity index score, enzyme-linked immunosorbent assay, and hematoxylin-eosin staining. Also, in vitro antioxidant activity of CCE was investigated by ABTS methods. Total phytochemical content of CCE was measured spectroscopically. Acetic acid caused colonic damage according to disease activity index and macroscopic scoring. CCE significantly reversed these damages. While the levels of proinflammatory cytokines TNF-alpha, IL-1beta, IL-6, and TGF-1beta increased in tissue with UC, IL-10 level decreased. CCE increased inflammatory cytokine levels to values close to the sham group. At the same time, while markers indicating disease severity such as VEGF, COX-2, PGE2, and 8-OHdG indicated the disease in the colitis group, these values returned to normal with CCE. Histological research results support biochemical analysis. CCE exhibited significant antioxidant against ABTS radical. Also, CCE was found to have a high content of total polyphenolic compounds. These findings provide evidence that CCE might be benefit as a promising novel therapy in the treatment of UC in humans due to high polyphenol content and justify the use of CC in folkloric medicine for treatment of inflamed diseases.

The NRF2/Keap1 pathway as a therapeutic target in inflammatory bowel disease

Oxidative stress (OS) is an important pathophysiological mechanism in inflammatory bowel disease (IBD). However, clinical trials investigating compounds directly targeting OS in IBD yielded mixed results. The NRF2 (nuclear factor erythroid 2-related factor 2)/Keap1 (Kelch-like ECH-associated protein 1) pathway orchestrates cellular responses to OS, and dysregulation of this pathway has been implicated in IBD. Activation of the NRF2/Keap1 pathway may enhance antioxidant responses. Although this approach could help to attenuate OS and potentially improve clinical outcomes, an overview of human evidence for modulating the NRF2/Keap1 axis and more recent developments in IBD is lacking. This review explores the NRF2/Keap1 pathway as potential therapeutic target in IBD and presents compounds activating this pathway for future clinical applications.

Role of extracted phytochemicals from Rosa sterilis S. D. Shi in DSS-induced colitis mice: potential amelioration of UC

Rosa sterilis S. D. Shi is a new variety of R. roxburghii Tratt and its fruits are rich in bioactive components, but its effects and mechanisms against intestinal inflammation are currently unknown. In this study, the main components of the ethanol extract of R. sterilis S. D. Shi fruits (RSE) were identified and its anti-inflammatory efficacy in DSS-induced mice was evaluated. A total of nine compounds were identified, including 1-O-E-cinnamoyl-(6-arabinosylglucose), ellagic acid-O-rhamnoside, (epi) catechin, niga-ichigoside F1, etc. The results demonstrated that RSE ameliorated DSS-induced inflammation in mouse colon tissues by increasing mucin expression, reducing the production of TNF-α, IL-1β, and IL-6, inhibiting the mRNA expression of COX-2 and iNOS, regulating the composition of gut microbiota through suppressing Escherichia-Shigella while increasing Akkermansia muciniphila, and promoting the production of SCFAs, especially acetic acid. Briefly, RSE showed outstanding potential for anti-inflammatory activity and is expected to be a promising dietary supplement for healthy individuals to prevent or relieve colitis and colitis-related diseases, which provided a new direction for functional food development.

The Importance of Antioxidant Activity for the Health-Promoting Effect of Lycopene

Lycopene is a compound of colored origin that shows strong antioxidant activity. The positive effect of lycopene is the result of its pleiotropic effect. The ability to neutralize free radicals via lycopene is one of the foundations of its pro-health effect, including the ability to inhibit the development of many civilization diseases. Therefore, this study focuses on the importance of the antioxidant effect of lycopene in inhibiting the development of diseases such as cardiovascular diseases, diseases within the nervous system, diabetes, liver diseases, and ulcerative colitis. According to the research mentioned, lycopene supplementation has significant promise for the treatment of illnesses marked by chronic inflammation and oxidative stress. However, the majority of the supporting data for lycopene's health benefits comes from experimental research, whereas the evidence from clinical studies is both scarcer and less certain of any health benefits. Research on humans is still required to establish its effectiveness.

Oxidative stress, hormones, and effects of natural antioxidants on intestinal inflammation in inflammatory bowel disease

Inflammatory bowel disease (IBD) is a chronic, relapsing gastrointestinal (GI) disorder characterized by intestinal inflammation. The etiology of IBD is multifactorial and results from a complex interplay between mucosal immunity, environmental factors, and host genetics. Future therapeutics for GI disorders, including IBD, that are driven by oxidative stress require a greater understanding of the cellular and molecular mechanisms mediated by reactive oxygen species (ROS). In the GI tract, oxidative stressors include infections and pro-inflammatory responses, which boost ROS generation by promoting the production of pro-inflammatory cytokines. Nuclear factor kappa B (NF-κB) and nuclear factor erythroid 2-related factor 2 (Nrf2) represent two important signaling pathways in intestinal immune cells that regulate numerous physiological processes, including anti-inflammatory and antioxidant activities. Natural antioxidant compounds exhibit ROS scavenging and increase antioxidant defense capacity to inhibit pro-oxidative enzymes, which may be useful in IBD treatment. In this review, we discuss various polyphenolic substances (such as resveratrol, curcumin, quercetin, green tea flavonoids, caffeic acid phenethyl ester, luteolin, xanthohumol, genistein, alpinetin, proanthocyanidins, anthocyanins, silymarin), phenolic compounds including thymol, alkaloids such as berberine, storage polysaccharides such as tamarind xyloglucan, and other phytochemicals represented by isothiocyanate sulforaphane and food/spices (such as ginger, flaxseed oil), as well as antioxidant hormones like melatonin that target cellular signaling pathways to reduce intestinal inflammation occurring with IBD.

A Combination of Polymethoxyflavones from Citrus sinensis and Prenylflavonoids from Humulus lupulus Counteracts IL-1β-Induced Differentiated Caco-2 Cells Dysfunction via a Modulation of NF-κB/Nrf2 Activation

We here investigated the anti-inflammatory activity of a polymethoxylated flavone-containing fraction (PMFF) from Citrus sinensis and of a prenylflavonoid-containing one (PFF) from Humulus lupulus, either alone or in combination (MIX). To this end, an in vitro model of inflammatory bowel disease (IBD), consisting of differentiated, interleukin (IL)-1β-stimulated Caco-2 cells, was employed. We demonstrated that non-cytotoxic concentrations of either PMFF or PFF or MIX reduced nitric oxide (NO) production while PFF and MIX, but not PMFF, also inhibited prostaglandin E2 release. Coherently, MIX suppressed both inducible NO synthase and cyclooxygenase-2 over-expression besides NF-κB activation. Moreover, MIX increased nuclear factor erythroid 2-related factor 2 (Nrf2) activation, heme oxygenase-1 expression, restoring GSH and reactive oxygen and nitrogen species (RONs) levels. Remarkably, these effects with MIX were stronger than those produced by PMFF or PFF alone. Noteworthy, nobiletin (NOB) and xanthohumol (XTM), two of the most represented phytochemicals in PMFF and PFF, respectively, synergistically inhibited RONs production. Overall, our results demonstrate that MIX enhances the anti-inflammatory and anti-oxidative effects of the individual fractions in a model of IBD, via a mechanism involving modulation of NF-κB and Nrf2 signalling. Synergistic interactions between NOB and XTM emerge as a relevant aspect underlying this evidence.

Polydopamine Modified Ceria Nanorods Alleviate Inflammation in Colitis by Scavenging ROS and Regulating Macrophage M2 Polarization

Background

Inflammatory bowel disease (IBD) is closely related to higher intracellular oxidative stress. Therefore, developing a novel method to scavenge the harmful reactive oxygen species (ROS) and alleviate colon inflammation to treat IBD is a promising strategy.

Methods

CeO2@PDA-PEG (CeO2@PP) were synthesized by modifying ceria (CeO2) nanorods with polydopamine (PDA) and polyethylene glycol (PEG). The ROS scavenging ability of CeO2@PP was detected by using flow cytometry and confocal laser scanning microscope (CLSM). The anti-inflammatory ability of CeO2@PP was determined in vitro by treating lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages. The biocompatibility of CeO2@PP was evaluated in vivo and in vitro. Moreover, the therapeutic effects of CeO2@PP in vivo were estimated in a dextran sulfate sodium salt (DSS)-induced colitis mouse model.

Results

Physicochemical property results demonstrated that PDA and PEG modification endowed CeO2 nanorods with excellent dispersibility and colloidal stability. CeO2@PP maintained superior enzyme-like activity, including superoxide dismutase (SOD) and catalase (CAT), indicating antioxidant ability. Moreover, in vitro results showed that CeO2@PP with PDA promotes LPS-induced RAW 264.7 macrophages into M2-type polarization. In addition, in vitro and in vivo results showed that CeO2@PP have great biocompatibility and biosafety. Animal experiments have shown that CeO2@PP have excellent anti-inflammatory effects against DSS-induced colitis and effectively alleviated intestinal mucosal injury.

Conclusion

The nanoplatform CeO2@PP possessed excellent antioxidant and anti-inflammatory properties for scavenging ROS and modulating macrophage polarization, which is beneficial for efficient colitis therapy.

miR-200a attenuated oxidative stress, inflammation, and apoptosis in dextran sulfate sodium-induced colitis through activation of Nrf2

Introduction

Oxidative stress and inflammatory responses are critical factors in ulcerative colitis disease pathogenesis. Nuclear factor erythroid 2-related factor 2 (Nrf2) modulates oxidative stress and suppresses inflammatory responses, and the protective benefits of Nrf2 activation have been associated with the therapy of ulcerative colitis. MicroRNA-200a (miR-200a) could target Kelch-like ECH-associated protein 1 (Keap1) and activate the Nrf2-regulated antioxidant pathway. Nevertheless, whether miR-200a modulates the Keap1/Nrf2 pathway in dextran sulfate sodium (DSS)-induced colonic damage is unknown. Here, our research intends to examine the impact of miR-200a in the model of DSS-induced colitis.

Methods

Prior to DSS intervention, we overexpressed miR-200a in mice for four weeks using an adeno-associated viral (AAV) vector to address this problem. ELISA detected the concentration of inflammation-related cytokines. The genes involved in inflammatory reactions and oxidative stress were identified using quantitative reverse transcription-polymerase chain reaction (qRT-PCR), western blot, and immunofluorescence. Moreover, we applied siRNAs to weakened Nrf2 expression to confirm the hypothesis that miR-200a provided protection via Nrf2.

Results

The present study discovered miR-200a down-regulation, excessive inflammatory activation, enterocyte apoptosis, colonic dysfunction, and Keap1/Nrf2 antioxidant pathway inactivation in mouse colitis and NCM460 cells under DSS induction. However, our data demonstrated that miR-200a overexpression represses Keap1 and activates the Nrf2 antioxidant pathway, thereby alleviating these adverse alterations in animal and cellular models. Significantly, following Nrf2 deficiency, we failed to observe the protective benefits of miR-200a against colonic damage.

Discussion

Taken together, through activating the Keap1/Nrf2 signaling pathway, miR-200a protected against DSS-induced colonic damage. These studies offer an innovative therapeutic approach for ulcerative colitis.

The role of Nrf2 in the pathogenesis and treatment of ulcerative colitis

Ulcerative colitis (UC) is a chronic inflammatory bowel disease involving mainly the colorectal mucosa and submucosa, the incidence of which has been on the rise in recent years. Nuclear factor erythroid 2-related factor 2 (Nrf2), known for its key function as a transcription factor, is pivotal in inducing antioxidant stress and regulating inflammatory responses. Numerous investigations have demonstrated the involvement of the Nrf2 pathway in maintaining the development and normal function of the intestine, the development of UC, and UC-related intestinal fibrosis and carcinogenesis; meanwhile, therapeutic agents targeting the Nrf2 pathway have been widely investigated. This paper reviews the research progress of the Nrf2 signaling pathway in UC.

Protective role of flavonoids quercetin and silymarin in the viral-associated inflammatory bowel disease: an updated review

Inflammatory bowel disease (IBD) is a chronic recurrent inflammation of the gastrointestinal tract (GIT). IBD patients are susceptible to various infections such as viral infections due to the long-term consumption of immunosuppressive drugs and biologics. The antiviral and IBD protective traits of flavonoids have not been entirely investigated. This study objective included an overview of the protective role of flavonoids quercetin and silymarin in viral-associated IBD. Several viral agents such as cytomegalovirus (CMV), Epstein-Barr virus (EBV), varicella zoster virus (VZV) and enteric viruses can be reactivated and thus develop or exacerbate the IBD conditions or eventually facilitate the disease remission. Flavonoids such as quercetin and silymarin are non-toxic and safe bioactive compounds with remarkable anti-oxidant, anti-inflammatory and anti-viral effects. Mechanisms of anti-inflammatory and antiviral effects of silymarin and quercetin mainly include immune modulation and inhibition of caspase enzymes, viral binding and replication, RNA synthesis, viral proteases and viral assembly. In the nutraceutical sector, natural flavonoids low bioavailability and solubility necessitate the application of delivery systems to enhance their efficacy. This review study provided an updated understanding of the protective role of quercetin and silymarin against viral-associated IBD.

Geniposide ameliorates dextran sulfate sodium-induced ulcerative colitis via KEAP1-Nrf2 signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

The dried fruit of Gardenia jasminoides Ellis (Zhizi in Chinese) is a traditional medicine used for thousands of years in China, Japan and Korea. Zhizi was recorded in Shennong Herbal, as a folk medicine, it reduces fever and treats gastrointestinal disturbance with antiphlogistic effects. Geniposide, an iridoid glycoside, is an important bioactive compound derived from Zhizi and possesses remarkable antioxidant and anti-inflammatory capacities. The pharmacological efficacy of Zhizi is highly related to the antioxidant and anti-inflammatory effects of geniposide.

AIM OF THE STUDY

Ulcerative colitis (UC) is a common chronic gastrointestinal disease as a global public health threat. Redox imbalance is an essential factor in the progression and recurrence of UC. This study aimed to explore the therapeutic effect of geniposide on colitis and uncover the underlying mechanisms of geniposide-mediated antioxidant and anti-inflammatory activities.

EXPERIMENTAL DESIGN

The study design involved investigating the novel mechanism by which geniposide ameliorates dextran sulfate sodium (DSS)-induced colitis in vivo and lipopolysaccharide (LPS)-challenged colonic epithelial cells in vitro.

MATERIALS AND METHODS

The protective effect of geniposide against colitis was evaluated by histopathologic observation and biochemical analysis of colonic tissues in DSS-induced colitis mice. The antioxidant and anti-inflammatory effects of geniposide were evaluated in both DSS-induced colitis mice and LPS-challenged colonic epithelial cells. Immunoprecipitation, drug affinity responsive target stability (DARTS), and molecular docking were performed to identify the potential therapeutic target of geniposide and the potential binding sites and patterns.

RESULTS

Geniposide ameliorated the symptoms of DSS-induced colitis and colonic barrier injury, inhibited pro-inflammatory cytokine expression, and suppressed activation of the NF-κB signaling in colonic tissues of DSS-challenged mice. Geniposide also ameliorated lipid peroxidation and restored redox homeostasis in DSS-treated colonic tissues. In addition, in vitro experiments also showed that geniposide exhibited significant anti-inflammatory and antioxidant activity, as evidenced by suppressed IκB-α and p65 phosphorylation and IκB-α degradation, and enhanced the phosphorylation and transcriptional activity of Nrf2 in LPS-treated Caco2 cells. ML385, a specific Nrf2 inhibitor, abolished the protective effect of geniposide against LPS-induced inflammation. Mechanistically, geniposide could bind to KEAP1, thereby disrupting the interaction between KEAP1 and Nrf2, preventing Nrf2 from degradation and activating the Nrf2/ARE signaling pathway, ultimately suppressing the onset of inflammation caused by redox imbalance.

CONCLUSIONS

Geniposide ameliorates colitis by activation of Nrf2/ARE signaling, while preventing colonic redox imbalance and inflammatory damage, indicating that geniposide can be considered as a promising lead compound for the treatment of colitis.

The possible effect of lycopene in ameliorating experimentally induced ulcerative colitis in adult male albino rats (A histological, immunohistochemical, and ultrastructural study)

Ulcerative colitis (UC) is considered a long-term inflammatory disorder worldwide. Its pathogenesis is associated with reduced antioxidant capacity. Lycopene (LYC) is a powerful antioxidant with strong free radical scavenging property. The present work has done to assess changes of colonic mucosa in induced UC and the possible ameliorative effects of LYC. Forty-five adult male albino rats were randomly divided into four groups: group I (control), group II was given 5 mg/kg/day (LYC) by oral gavage for 3 weeks. Group III (UC) was received single intra-rectal injection of acetic acid. Group IV (LYC+UC) received LYC in same dose and duration as before and acetic acid on 14th day of the experiment. UC group showed loss of surface epithelium with destructed crypts. Congested blood vessels with heavy cellular infiltration were observed. Significant decrease in goblet cell numbers and the mean area percentage of ZO-1 immunoexpression were noticed. Significant increase in the mean area percentage of collagen and the mean area percentage of COX-2 were also noticed. Ultrastructural changes were matched with light microscopic results that showed abnormal destructive columnar and goblet cells. Histological, immunohistochemical, and ultrastructural findings in group IV supported the ameliorative role of LYC against destructive changes induced by UC.

Production of glutathione from probiotic Bacillus amyloliquefaciens KMH10 using banana peel extract

Glutathione, a tri-peptide (glutamate-cysteine-glycine) with the thiol group (-SH), is most efficient antioxidative agent in eukaryotic cells. The present study aimed to isolate an efficient probiotic bacterium having the potential to produce glutathione. The isolated strain Bacillus amyloliquefaciens KMH10 showed antioxidative activity (77.7 ± 2.56) and several other essential probiotic attributes. Banana peel, a waste of banana fruit, is chiefly composed of hemicellulose with various minerals and amino acids. A consortium of lignocellulolytic enzyme was used for the saccharifying banana peel to produce 65.71 g/L sugar to support the optimal glutathione production of 181 ± 4.56 mg/L; i.e., 1.6 folds higher than the control. So, the studied probiotic bacteria could be an effective resource for glutathione; therefore, the stain could be used as natural therapeutics for the prevention/treatment of different inflammation-related gastric ailments and as an effective producer of glutathione using valorized banana waste that has excellent industrial relevance.

Protective Effects of H2S Donor Treatment in Experimental Colitis: A Focus on Antioxidants

Inflammatory bowel diseases (IBD) are chronic, inflammatory disorders of the gastrointestinal (GI) system, which have become a global disease over the past few decades. It has become increasingly clear that oxidative stress plays a role in the pathogenesis of IBD. Even though several effective therapies exist against IBD, these might have serious side effects. It has been proposed that hydrogen sulfide (H₂S), as a novel gasotransmitter, has several physiological and pathological effects on the body. Our present study aimed to investigate the effects of H₂S administration on antioxidant molecules in experimental rat colitis. As a model of IBD, 2,4,6-trinitrobenzenesulfonic acid (TNBS) was used intracolonically (i.c.) to induce colitis in male Wistar-Hannover rats. Animals were orally treated (2 times/day) with H₂S donor Lawesson's reagent (LR). Our results showed that H₂S administration significantly decreased the severity of inflammation in the colons. Furthermore, LR significantly suppressed the level of oxidative stress marker 3-nitrotyrosine (3-NT) and caused a significant elevation in the levels of antioxidant GSH, Prdx1, Prdx6, and the activity of SOD compared to TNBS. In conclusion, our results suggest that these antioxidants may offer potential therapeutic targets and H₂S treatment through the activation of antioxidant defense mechanisms and may provide a promising strategy against IBD.

Ameliorative Effect of Aqueous and Hydroalcoholic Extracts of Scrophularia striata Boiss. on Murine Model of Experimental Colitis

Background

Scrophularia striata Boiss. (S. striata) is a flowering plant with several therapeutic properties including antiinflammatory, antioxidant, antimicrobial, and wound-healing activity. Regarding the side effects of drugs conventionally used for inflammatory bowel disease (IBD) treatment, we investigated the anticolitis properties of aqueous (SSAE) and hydroalcoholic (SSHE) extracts of S. striata on experimental colitis.

Materials and Methods

The colitis was induced using acetic acid (3%) and 2 h before ulcer induction, each group of rats received orally three doses (150, 300, and 600 mg/kg, p.o.) of SSAE or SSHE for the next 5 days. Dexamethasone (1 mg/kg, i.p.) and mesalazine (100 mg/kg, p.o.) were used as reference drugs. Different parameters including weight of colon/height, ulcer index, total colitis index, levels of myeloperoxidase (MPO) and malondialdehyde (MDA) were investigated.

Results

Total phenolic contents were 4.3 ± 0.2 and 7.1 ± 0.4 mg/g equivalent to gallic acid for SSAE and SSHE respectively. Three applied doses of SSHE and the highest dose of SSAE (600 mg/kg) could reduce all the macroscopic and pathologic indices of colitis and the levels of MPO and MDA. Two lesser doses of SSAE (150, 300 mg/kg) however, couldn't diminish the histopathologic features of colitis and the values of MPO and MDA.

Conclusions

S. striata, especially SSHE, which also contained more phenolic compounds, had an ameliorating effect on ulcerative colitis and possibly exerts this effect through its antioxidant, antiinflammatory and wound healing properties. Further investigations are required to introduce this plant as a novel alternative herbal drug for colitis treatment.

Pro- and Antioxidant Effect of Food Items and Matrices during Simulated In Vitro Digestion

The digestive tract can be considered a bioreactor. High levels of reactive oxygen species (ROS) during digestion may predispose for local and/or systemic oxidative stress and inflammation, e.g., inflammatory bowel diseases. Food items rich in antioxidants may prevent such aggravation. This investigation analyzed pro-and antioxidant patterns of food matrices/items following in vitro digestion. Gastrointestinal digestion reflecting typically consumed quantities was performed on nine food items (orange and tomato juice, soda, coffee, white chocolate, sausage, vitamin C and E, and curcumin) and their combinations (n = 24), using the INFOGEST model. Antioxidant potential was measured by FRAP, DPPH, and ABTS, and pro-oxidant aspects by MDA (malondialdehyde) and peroxide formation. An anti-pro-oxidant score was developed, combining the five assays. Liquid food items showed moderately high antioxidant values, except for coffee and orange juice, which exhibited a high antioxidant potential. Solid matrices, e.g., white chocolate and sausage, showed both high pro-oxidant (up to 22 mg/L MDA) and high antioxidant potential (up to 336 mg/L vitamin C equivalents) at the same time. Individual vitamins (C and E) at physiological levels (achievable from food items) showed a moderate antioxidant potential (<220 mg/L vitamin C equivalents). Overall, both antioxidant and pro-oxidant assays correlated well, with correlation coefficients of up to 0.894. The effects of food combinations were generally additive, i.e., non-synergistic, except for combinations with sausage, where strong quenching effects for MDA were observed, e.g., with orange juice. In conclusion, as especially highlighted by complex matrices demonstrating both pro- and antioxidant potential, only measuring one aspect would result in physiological misinterpretations. Therefore, it is imperative to employ a combination of assays to evaluate both pro- and antioxidant properties of food digesta to ensure physiological relevance.

Natural Coumarin Derivatives Activating Nrf2 Signaling Pathway as Lead Compounds for the Design and Synthesis of Intestinal Anti-Inflammatory Drugs

Nrf2 (nuclear factor erythroid 2-related factor 2) is a transcription factor related to stress response and cellular homeostasis that plays a key role in maintaining the redox system. The imbalance of the redox system is a triggering factor for the initiation and progression of non-communicable diseases (NCDs), including Inflammatory Bowel Disease (IBD). Nrf2 and its inhibitor Kelch-like ECH-associated protein 1 (Keap1) are the main regulators of oxidative stress and their activation has been recognized as a promising strategy for the treatment or prevention of several acute and chronic diseases. Moreover, activation of Nrf2/keap signaling pathway promotes inhibition of NF-κB, a transcriptional factor related to pro-inflammatory cytokines expression, synchronically promoting an anti-inflammatory response. Several natural coumarins have been reported as potent antioxidant and intestinal anti-inflammatory compounds, acting by different mechanisms, mainly as a modulator of Nrf2/keap signaling pathway. Based on in vivo and in vitro studies, this review focuses on the natural coumarins obtained from both plant products and fermentative processes of food plants by gut microbiota, which activate Nrf2/keap signaling pathway and produce intestinal anti-inflammatory activity. Although gut metabolites urolithin A and urolithin B as well as other plant-derived coumarins display intestinal anti-inflammatory activity modulating Nrf2 signaling pathway, in vitro and in vivo studies are necessary for better pharmacological characterization and evaluation of their potential as lead compounds. Esculetin, 4-methylesculetin, daphnetin, osthole, and imperatorin are the most promising coumarin derivatives as lead compounds for the design and synthesis of Nrf2 activators with intestinal anti-inflammatory activity. However, further structure-activity relationships studies with coumarin derivatives in experimental models of intestinal inflammation and subsequent clinical trials in health and disease volunteers are essential to determine the efficacy and safety in IBD patients.

Cornus mas L. Extract Targets the Specific Molecules of the Th17/Treg Developmental Pathway in TNBS-Induced Experimental Colitis in Rats

Given that one of the crucial events in the pathogenesis of inflammatory bowel disease is the loss of homeostasis between Th17 and Treg cells, targeting the specific molecules of the Th17/Treg axis developmental pathway is a promising strategy for inflammatory bowel disease prevention and treatment. The current study aimed to assess the impact of cornelian cherry (Cornus mas L.) extract, rich in iridoids and polyphenols known for their potential anti-inflammatory activity, at two doses (20 or 100 mg/kg) on the crucial factors for Th17/Treg cell differentiation in the course of experimental colitis and compare this action with that of sulfasalazine. This study was conducted on the biobank colon tissue samples collected during the previous original experiment, in which colitis in rats was induced by trinitrobenzenesulfonic acid (TNBS). The levels of IL-6, RORγt, total STAT3, p-STAT3, and Foxp3 were determined by ELISA. The expression of PIAS3 mRNA was quantified by qPCR. Cornelian cherry extract at a dose of 100 mg/kg counteracted the TNBS-induced elevation of IL-6, RORγt, and p-STAT3 levels and a decrease in Foxp3 level and PIAS3 mRNA expression, while given concomitantly with sulfasalazine was more effective than sulfasalazine alone in reversing the TNBS-induced changes in IL-6, RORγt, total STAT3, p-STAT3, Foxp3 levels, and PIAS3 mRNA expression. The beneficial effect of cornelian cherry extract on experimental colitis may be due to its immunomodulatory activity reflected by the influence on factors regulating the Th17/Treg axis.

Antioxidative and Protective Effect of Morchella esculenta against Dextran Sulfate Sodium-Induced Alterations in Liver

Morchella esculenta is an edible mushroom with special flavor and high nutritional value for humans, primarily owing to its polysaccharide constituents. M. esculenta polysaccharides (MEPs) possess remarkable pharmaceutical properties, including antioxidant, anti-inflammatory, immunomodulatory, and anti-atherogenic activities. The aim of this study was to evaluate the in vitro and in vivo antioxidant potential of MEPs. In vitro activity was determined using free radical scavenging assays, whereas in vivo activity was evaluated through dextran sodium sulfate (DSS)-induced liver injury in mice with acute colitis. MEPs effectively scavenged 1,1-diphenyl-2-picrylhydrazyl and 2,2-azinobis-6-(3-ethylbenzothiazoline sulfonic acid) free radicals in a dose-dependent manner. Additionally, DSS-induced mice showed severe liver damage, cellular infiltration, tissue necrosis, and decreased antioxidant capacity. In contrast, intragastric administration of MEPs showed hepatoprotective effects against DSS-induced liver injury. MEPs remarkably elevated the expression levels of superoxide dismutase, glutathione peroxidase, and catalase. Additionally, it decreased malondialdehyde and myeloperoxidase levels in the liver. These results indicate that the protective effects of MEP against DSS-induced hepatic injury could rely on its ability to reduce oxidative stress, suppress inflammatory responses, and improve antioxidant enzyme activity in the liver. Therefore, MEPs could be explored as potential natural antioxidant agents in medicine or as functional foods to prevent liver injury.

The high dose of inulin exacerbated food allergy through the excess accumulation of short-chain fatty acids in a BABL/c mouse model

Inulin dietary supplement is conventionally beneficial to gut health and can potentially prevent food allergy (FA). This study aimed to determine how dietary inulin interventions at different doses affect the OVA-induced FA in a BALB/c mouse model. Although the middle dose of inulin (50 mg per mouse) showed the best therapeutic effect on FA, high-inulin supplementation (80 mg per mouse) provoked severe allergic and intestinal inflammatory responses, which were characterized by elevated serum allergic inflammation-related factor levels, dysfunctional gut barrier, unbalanced luminal pH value, decrease in intestinal antioxidant capacity, and disordered gut microecology. Moreover, profiling of SCFAs indicated that the high-inulin-induced excess accumulation of SCFAs in the colon was responsible for the gut immune disorders. Spearman correlation analysis unraveled that the featured bacterial taxa in the high-inulin-treated mice were Ruminococcaceae and Bifidobacterium, of which the relative abundance was negatively correlated with expression of tight junction proteins and improvement of T cell homeostasis, and positively correlated with levels of allergic inflammation-related indexes. Our work suggested that high-inulin dietary supplementation can be detrimental to allergic individuals and highlighted the importance for personalized use of inulin-type dietary supplements to safely improve human health.

In vitro digestion and human gut microbiota fermentation of Bletilla striata polysaccharides and oligosaccharides

Background

Bletilla striata is one of the commonly used traditional Chinese medicine. B. striata polysaccharides (BP) and oligosaccharides (BO) are one of the main components of B. striata, which have been proved to have a variety of biological activities. However, the digestion and fermentation characteristics of BP and BO are still unclear.

Methods

The study evaluated different prebiotic effects of BP and BO by in vitro simulating digestion and gut microbiota fermentation.

Results

The results show that the simulating saliva partly degraded BP, but had no effect on BO. The molecular weights of BP and BO remained basically unchanged in gastric and intestinal digestion. In addition, BP and BO could be rapidly degraded and utilized by gut microbiota. During in vitro fermentation, the growth rates of the BP and BO groups were higher than that of the Control group and the pH value and total carbohydrate content in BP group and BO group decreased significantly. Although the reducing sugar level in the BO group decreased rapidly, it remained at a low level in the BP group. Both BP and BO improved the composition and structure of gut microbiota, indicative of the upregulated abundances of Streptococcus and Veillonella, and the downregulated populations of Escherichia and Bacteroides. There were differences in the SCFA production by gut microbiota and antioxidant activities between the BP and BO groups. The fermentation broth of the BP group displayed a stronger suppression of O₂-, but a higher scavenging effect on DPPH for the BO group.

Conclusions

BP and BO displayed different digestion and fermentation characteristics in vitro due to their distinct polymerization degrees. The study point towards the potential of BP and BO as prebiotics in the application to human diseases by selectively regulating gut microbiota in the future.

Antioxidant properties of fermented soymilk and its anti-inflammatory effect on DSS-induced colitis in mice

Lactic acid-fermented soymilk as a new plant-based food has aroused extensive attention because of its effects on nutrition and health. This study was conducted to delve into the antioxidative and anti-inflammatory activities of lactic acid-fermented soymilk. To elucidate the key factors that affect the antioxidant properties of fermented soymilk, the strains and preparation process were investigated. Findings show that the fermented soymilk prepared using hot-water blanching method (BT-80) demonstrated a better antioxidant activity than that using conventional method (CN-20). Besides, a huge difference was observed among the soymilks fermented with different strains. Among them, the YF-L903 fermented soymilk demonstrated the highest ABTS radical scavenging ability, which is about twofold of that of unfermented soymilk and 1.8-fold of that of L571 fermented soy milk. In vitro antioxidant experiments and the analysis of H₂O₂-induced oxidative damage model in Caco-2 cells showed that lactic acid-fermentation could improve the DPPH radical scavenging ability, ABTS radical scavenging ability, while reducing the content of reactive oxygen species (ROS) and malondialdehyde (MDA) in Caco-2 cells induced by H₂O₂, and increasing the content of superoxide dismutase (SOD). Consequently, cells are protected from the damage caused by active oxidation, and the repair ability of cells is enhanced. To identify the role of fermented soymilk in intestinal health, we investigate its preventive effect on dextran sodium sulfate-induced colitis mouse models. Results revealed that the fermented soymilk can significantly improve the health conditions of the mice, including alleviated of weight loss, relieved colonic injury, balanced the spleen-to-body weight ratio, reduced the disease index, and suppressed the inflammatory cytokines and oxidant indexes release. These results suggest that YF-L903 fermented soymilk is a promising natural antioxidant sources and anti-inflammatory agents for the food industry. We believe this work paves the way for elucidating the effect of lactic acid-fermented soymilk on intestinal health, and provides a reference for the preparation of fermented soymilk with higher nutritional and health value.

Cloning and expression of recombinant human superoxide dismutase 1 (hSOD1) in Bacillus subtilis 1012

OBJECTIVE

We aimed to clone and express the human Cu, Zn superoxide dismutase (hSOD1) in Bacillus subtilis 1012. Also, we investigated the expression level of hSOD1 under different induction conditions.

RESULT

As an essential member of the antioxidant defense system in vivo, hSOD1 has become a therapeutic agent against host diseases, such as oxygen toxicity, acute inflammation, and radiation injury. The recombinant hSOD1 was successfully secreted extracellularly into B. subtilis 1012. The expression conditions were optimized, including inoculum size, different media, temperatures, and inducer concentrations. Finally, the highest level of hSOD1 was produced as a soluble form in Super rich medium by 2% inoculum with 0.2 mM of IPTG at 37 °C after the induction for 24 h. Besides, 20 g/L of lactose also displayed the same inductive effect on hSOD1 expression as that of IPTG (0.2 mM). Finally, the specific activity of purified hSOD1 was determined to be 1625 U/mg in the presence of 800 μM of Cu²⁺ and 20 μM of Zn²⁺.

CONCLUSIONS

We propose that the B. subtilis 1012-hSOD1 strain system has great potential in future industrial applications.

Mactanamide and lariciresinol as radical scavengers and Fe2+ ion chelators - A DFT study

A DFT based kinetic study of OOH radical scavenging potency of mactanamide (MA) and lariciresinol (LA), two natural polyphenols, indicates their nearly equal potential via the proton coupled electron transfer (PCET) mechanism in lipid media. Contribution of C-H bond breaking to this potency is negligible compared to O-H bond breaking, contrary to recent claims. The predicted potency of both compounds is not sufficient to protect biological molecules from oxidative damage in lipid media. In aqueous media, the scavenging potency of MA and LA phenoxide anions via the single electron transfer (SET) mechanism is much higher and may contribute to the protection of lipids, proteins, and DNA from OOH radical damage. Also, MA and LA have the potential to chelate catalytic Fe2+ ions, thus suppressing the formation of dangerous OH radicals via Fenton-type reactions. The monoanionic species of MA and LA show stronger monodentate chelating ability with Fe2+ ion compared to its neutral form. The dianionic specie LA2- exhibited the highest chelation ability with Fe2+ ion via bidentate 1:2 coordination. However, direct radical scavenging and metal chelation could be rarely operative in vivo because MA and LA presumably achieve very low concentrations in systemic circulation.

Targeting pathophysiological changes using biomaterials-based drug delivery systems: A key to managing inflammatory bowel disease

Inflammatory bowel disease (IBD) is a gastrointestinal disorder, affecting about several million people worldwide. Current treatments fail to adequately control some clinical symptoms in IBD patients, which can adversely impact the patient's quality of life. Hence, the development of new treatments for IBD is needed. Due to their unique properties such as biocompatibility and sustained release of a drug, biomaterials-based drug delivery systems can be regarded as promising candidates for IBD treatment. It is noteworthy that considering the pathophysiological changes occurred in the gastrointestinal tract of IBD patients, especially changes in pH, surface charge, the concentration of reactive oxygen species, and the expression of some biomolecules at the inflamed colon, can help in the rational design of biomaterials-based drug delivery systems for efficient management of IBD. Here, we discuss about targeting these pathophysiological changes using biomaterials-based drug delivery systems, which can provide important clues to establish a strategic roadmap for future studies.

Preventive Effect of Vitamin C on Dextran Sulfate Sodium (DSS)-Induced Colitis via the Regulation of IL-22 and IL-6 Production in Gulo(−/−) Mice

Reactive oxygen species (ROS), which are exceptionally high in IBD lesions, are known to cause abnormal immune responses to inflammatory reactions in inflammatory bowel diseases (IBD) through damage to the intestinal mucosal linings. Moreover, they are theorized to be an agent of IBD development. Vitamin C is widely known to be an effective antioxidant for its ability to regulate inflammatory responses through its ROS scavenging effect. Therefore, we examined vitamin C’s influence on the development and progression of IBD in Gulo(−/−) mice, which cannot synthesize vitamin C like humans due to a defect in the expression of L-gulono-γ–lactone oxidase, an essential enzyme for vitamin C production. First, we found extensive oxidative stress and an inflammation increase in the colon of vitamin C-insufficient Gulo(−/−) mice. We also found decreased IL-22 production and NKp46(+) cell recruitment and the impaired activation of the p38MAPK pathway. Additionally, comparing vitamin C-insufficient Gulo(−/−) mice to vitamin C-sufficient Gulo(−/−) mice and wild-type mice, the insufficient group faced a decrease in mucin-1 expression, accompanied by an increase in IL-6 production, followed by the activation of the STAT3 and Akt pathways. The results suggest that vitamin C insufficiency induces severe colitis, meaning vitamin C could also take on a preventative role by regulating the production of cytokines and the induction of inflammation.

Targeting Lineage-Specific Transcription Factors and Cytokines of the Th17/Treg Axis by Novel 1,3,4-Oxadiazole Derivatives of Pyrrolo[3,4-d]pyridazinone Attenuates TNBS-Induced Experimental Colitis

The pharmacotherapy of inflammatory bowel disease (IBD) is still not fully effective and safe. Attempts to search for new IBD drugs remain an incessant research aim. One of the novel approaches is targeting the developmental pathway molecules and effector cytokines of Th17/Treg axis. This study aimed to elucidate the impact of new pyrrolo[3,4-d]pyridazinone derivatives, compounds 7b, 10b, or 13b, on the course of experimental colitis in rats and to assess whether these new compounds may influence Th17/Treg axis. Rats were pretreated with studied compounds intragastrically before intrarectal administration of 2,4,6-trinitrobenzenesulfonic acid used for colitis induction. Body weight loss, disease activity index, colon index, and colon tissue damage were analyzed to evaluate the severity of colitis. The colonic levels of RORγt, STAT3, CCR6, Foxp3, IL-6, IL-10, IL-17, TNF-α, IL-23, and PGE₂ were assessed. Pretreatment with compounds 7b and 13b alleviated the severity of colitis and concomitantly counteracted the increased levels of RORγt, STAT3, CCR6, IL-6, IL-17, IL-23, TNF-α, and PGE₂. The beneficial effect of compounds 7b and 13b may be due to the decrease in the levels of Th17-specific transcription factors and cytokines. The studied compounds might therefore constitute a promising therapeutic strategy in Th17/Treg imbalance-driven inflammatory conditions such as IBD.

Ulva pertusa, a Marine Green Alga, Attenuates DNBS-Induced Colitis Damage via NF-κB/Nrf2/SIRT1 Signaling Pathways

Inflammatory bowel diseases (IBD) including Crohn's disease (CD) and ulcerative colitis (UC) represent gastrointestinal (GI) disorders associated with varied responses to microbial and environmental agents. Natural compounds have been suggested as a valid approach to the management of various GI diseases, particularly the green alga Ulva pertusa, belonging to the Ulvaceae family, which showed powerful biological properties. Here, we aimed to evaluate the effect and the mechanism of Ulva pertusa treatments in a murine model of DNBS-induced colitis. Colitis was induced by DNBS intrarectal installation (4 mg in 100 μL of 50% ethanol), while Ulva pertusa treatments (doses of 10, 50 and 100 mg/kg) were administered orally daily. Ulva pertusa, at the higher doses of 50 and 100 mg/kg, significantly reduced tissue damage DNBS-induced and the consequent inflammatory cascade via NF-κB inhibition. Furthermore, we demonstrated, for the first time, Ulva pertusa action on the SIRT1/Nrf2 axis, enhancing antioxidant response and the modulation of the apoptosis pathway colitis-induced, regulating the expression of p53, Bax, Bcl-2, and Caspases. Taken together, Ulva pertusa could be considered a valid approach for counteracting and blocking the progression of IBDs through modulation of the NF-κB/SIRT1/Nrf2 axis.

Biological Activities Underlying the Therapeutic Effect of Quercetin on Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) is a chronic autoimmune disorder stemming from unrestrained immune activation and subsequent destruction of colon tissue. Genetic susceptibility, microbiota remodeling, and environmental cues are involved in IBD pathogenesis. Up to now, there are limited treatment options for IBD, so better therapies for IBD are eagerly needed. The therapeutic effects of naturally occurring compounds have been extensively investigated, among which quercetin becomes an attractive candidate owing to its unique biochemical properties. To facilitate the clinical translation of quercetin, we aimed to get a comprehensive understanding of the cellular and molecular mechanisms underlying the anti-IBD role of quercetin. We summarized that quercetin exerts the anti-IBD effect through consolidating the intestinal mucosal barrier, enhancing the diversity of colonic microbiota, restoring local immune homeostasis, and restraining the oxidative stress response. We also delineated the effect of quercetin on gut microbiome and discussed the potential side effects of quercetin administration. Besides, quercetin could serve as a prodrug, and the bioavailability of quercetin is improved through chemical modifications or the utilization of effective drug delivery systems. Altogether, these lines of evidence hint the feasibility of quercetin as a candidate compound for IBD treatment.

Lupin Protein Concentrate as a Novel Functional Food Additive That Can Reduce Colitis-Induced Inflammation and Oxidative Stress

Food fortification with bioactive compounds may constitute a way to ameliorate inflammatory bowel diseases (IBDs). Lupin seeds contain an oligomer named deflamin that can reduce IBD’s symptoms via MMP-9 inhibition. Here, our goal was to develop a lupin protein concentrate (LPC) enriched in deflamin and to test its application as a food additive to be used as a functional food against colitis. The nutritional profile of the LPC was evaluated, and its efficacy in vivo was tested, either alone or as added to wheat cookies. The LPC presented high protein and carbohydrate contents (20.09 g/100 g and 62.05/100 g, respectively), as well as antioxidant activity (FRAP: 351.19 mg AAE/10 mg and DPPH: 273.9 mg AAE/10 mg). It was also effective against TNBS-induced colitis in a dose dependent-manner, reducing DAI scores by more than 50% and concomitantly inhibiting MMP-9 activity. When added to cookies, the LPC activities were maintained after baking, and a 4-day diet with LPC cookies induced a significant protective effect against acetic acid-induced colitis, overall bringing lesions, oxidative stress and DNA damage levels to values significantly similar to controls (p < 0.001). The results show that the LPC is an efficient way to deliver deflamin in IBD-targeted diets.

Dual roles of the caspase-11 non-canonical inflammasome in inflammatory bowel disease

Inflammation is a two-step process comprising the first priming step that prepares inflammatory responses and the second triggering step that activates inflammatory responses. The key feature of the triggering step is the activation of inflammasomes and intracellular inflammatory protein complexes that provide molecular platforms to activate inflammatory signal transduction cascades. Although canonical inflammasomes have been well demonstrated to be actively involved in numerous human diseases, the roles of the recently identified non-canonical inflammasomes are largely unknown. However, recent studies have demonstrated the emerging roles of the caspase-11 non-canonical inflammasome in various human inflammatory diseases, ultimately providing strong evidence that the caspase-11 non-canonical inflammasome is a key player in the pathogenesis of various human diseases. Here, we comprehensively reviewed the regulatory roles of the caspase-11 non-canonical inflammasome in the pathogenesis of inflammatory bowel disease (IBD) and its underlying mechanisms. Overall, this review highlights the current understanding of the regulatory roles of the caspase-11 non-canonical inflammasome in IBD and may provide insight into new strategies for preventing and treating IBD and caspase-11 non-canonical inflammasome-driven diseases.

Coriolus Versicolor Downregulates TLR4/NF-κB Signaling Cascade in Dinitrobenzenesulfonic Acid-Treated Mice: A Possible Mechanism for the Anti-Colitis Effect

Inflammatory bowel diseases (IBDs) are disorders characterized by chronic inflammation of the intestinal tract. The focus of the present study was to examine the effect of the fungus Coriolus versicolor (CV), underlining its correlation with Toll-like receptors 4 (TLR4) and nuclear factor erythroid 2-related factor 2 (Nrf2); we aim to evaluate its anti-inflammatory and antioxidant effect in mice exposed to experimental colitis. The model was induced in mice by colon instillation of dinitrobenzenesulfonic acid (DNBS), CV was administered orally (200 mg per kg) daily for 4 days. On day 4, the animals were killed, and the tissues collected for histological, biochemical, and molecular analyses. Four days after DNBS administration, CC motif chemokine ligand 2 (CCL2), prostaglandin E2 (PGE2), interleukin-1β (IL-1β), and tumor necrosis factor-α (TNF-α) production increased in association with damage to the colon. Neutrophil infiltration, as assessed by myeloperoxidase (MPO) activity, in the mucosa was associated with overexpression of P-selectin and intercellular adhesion molecule 1 (ICAM1). Immunohistochemistry for nitrotyrosine and poly-(ADP-Ribose)-polymerase (PARP) showed evident stain in the inflamed colon. Treatment with CV significantly reduced the appearance of colon changes and weight loss. These effects were associated with a remarkable ability of CV to reduce the expression of TLR4 and modulate the pathway of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-kB). This improved the colon architecture, reduced MPO activity, the release of proinflammatory cytokines, the presence of nitrotyrosine, and the hyperactivation of PARP, as well as the up-regulation of P-selectin and ICAM1. Furthermore, we studied the action of CV on the Nrf2/HO-1 pathway, which is important for maintaining redox balance, demonstrating that CV by significantly increasing both enzymes is able to counteract the oxidative stress induced by DNBS. Taken together, our results clearly show that this natural compound can be considered as a possible dietary supplement against colitis.

Ficus pandurata Hance Inhibits Ulcerative Colitis and Colitis-Associated Secondary Liver Damage of Mice by Enhancing Antioxidation Activity

Inflammatory bowel disease (IBD), a global disease threatening human health, is commonly accompanied by secondary liver damage (SLD) mediated by the gut-liver axis. Oxidative stress acts a critical role in the onset of IBD, during which excessive oxidation would destroy the tight junctions between intestinal cells, promote proinflammatory factors to penetrate, and thereby damage the intestinal mucosa. Ficus pandurata Hance (FPH) is widely used for daily health care in South China. Our previous study showed that FPH protected acute liver damage induced by alcohol. However, there is no study reporting FPH treating ulcerative colitis (UC). This study is designed to investigate whether FPH could inhibit UC and reveal its potential mechanism. The results showed that FPH significantly alleviated the UC disease symptoms including the body weight loss, disease activity index (DAI), stool consistency changing, rectal bleeding, and colon length loss of UC mice induced by dextran sulfate sodium (DSS) and reversed the influences of DSS on myeloperoxidase (MPO) and diamine oxidase activity (DAO). FPH suppressed UC via inhibiting the TLR4/MyD88/NF-κB pathway and strengthened the gut barrier of mice via increasing the expressions of ZO-1 and occludin and enhancing the colonic antioxidative stress property by increasing the levels of T-SOD and GSH-Px and the expressions of NRF2, HO-1, and NQO1 and reducing MDA level and Keap1, p22-phox, and NOX2 expressions. Furthermore, FPH significantly inhibited SLD related to colitis by reducing the abnormal levels of the liver index, ALT, AST, and cytokines including TNFα, LPS, LBP, sCD14, and IL-18 in the livers, as well as decreasing the protein expressions of NLRP3, TNFα, LBP, CD14, TLR4, MyD88, NF-κB, and p-NF-κB, suggesting that FPH alleviated UC-related SLD via suppressing inflammation mediated by inhibiting the TLR4/MyD88/NF-κB pathway. Our study firstly investigates the anticolitis pharmacological efficacy of FPH, suggesting that it can be enlarged to treat colitis and colitis-associated liver diseases in humans.

Protective Effect of Salvianolic Acid B in Acetic Acid-Induced Experimental Colitis in a Mouse Model

In its prominent experimental studies salvianolic acid B (Sal B) is novel because of its well-defined, common physiological effects, which include anti-inflammatory, anti-depressant, cardioprotective, DNA protective, neuroprotective and hepatoprotective activity in experimental animals. Initially, Sal B was studied for its anti-inflammatory properties, used as a remedy for a wide range of disease conditions, but its specific efficacy on inflammatory bowel disease is still unclear. The aim of this current study was to understand the therapeutic potential of Sal B in an acetic acid (AA)—triggered experimental mouse colitis model. Colitis was triggered by intrarectal injection of 5% AA, and then laboratory animals were given Sal B (10, 20 and 40 μg/kg) for seven days. The ulcerated colonic mucosa was assessed by clinical experiment, macroscopical, biological and histopathological analysis. The results showed depleted SOD, CAT, GSH levels and consequential elevated MPO and MDA levels and aberrant crypt foci and mast cells were seen in the AA-induced colonic mucosa of experimental animals. The data obtained from this study demonstrate that a dose of 40 µg/kg showed an efficacious anti-ulcer effect against AA-induced experimental colitis. Based on its antioxidant efficacy, Sal B may therefore be useful as a therapeutic approach for ulcerative colitis.